Added skeleton code for register endpoint (#2)

Reviewed-on: phoenix/textsender-auth#2
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/model/model.go

@@ -0,0 +1 @@
+package model

internal/model/user.go

@@ -0,0 +1,120 @@
+package model
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type User struct {
+	Id          uuid.UUID `json:"id"`
+	PhoneNumber string    `json:"phone_number"`
+	Username    string    `json:"username"`
+	Password    string    `json:"password"`
+}
+
+type UserStore interface {
+	CreateUser(ctx context.Context, user *User) error
+	GetUserByID(ctx context.Context, id uuid.UUID) (*User, error)
+	GetUserByUsername(ctx context.Context, username string) (*User, error)
+	GetAllUsers(ctx context.Context) ([]*User, error)
+	UserExists(ctx context.Context, email string) (bool, error)
+}
+
+type PGUserStore struct {
+	db *pgxpool.Pool
+}
+
+func NewUserStore(db *pgxpool.Pool) *PGUserStore {
+	return &PGUserStore{db: db}
+}
+
+func (s *PGUserStore) CreateUser(ctx context.Context, user *User) error {
+	query := `
+		INSERT INTO users (phone_number, username, password)
+		VALUES ($1, $2, $3)
+		RETURNING id, phone_number, username
+	`
+
+	return s.db.QueryRow(ctx, query, user.PhoneNumber, user.Username, user.Password).Scan(
+		&user.Id, &user.PhoneNumber, &user.Username,
+	)
+}
+
+func (s *PGUserStore) GetUserByID(ctx context.Context, id uuid.UUID) (*User, error) {
+	query := `SELECT id, username, password, phone_number FROM users WHERE id = $1`
+
+	var user User
+	err := s.db.QueryRow(ctx, query, id).Scan(
+		&user.Id, &user.Username, &user.Password, &user.PhoneNumber,
+	)
+
+	if err == pgx.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("getting user by ID: %w", err)
+	}
+
+	return &user, nil
+}
+
+func (s *PGUserStore) GetUserByUsername(ctx context.Context, username string) (*User, error) {
+	query := `SELECT id, username, password, phone_number FROM users WHERE username = $1`
+
+	var user User
+	err := s.db.QueryRow(ctx, query, username).Scan(
+		&user.Id, &user.Username, &user.Password, &user.PhoneNumber,
+	)
+
+	if err == pgx.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("getting user by ID: %w", err)
+	}
+
+	return &user, nil
+}
+
+func (s *PGUserStore) GetAllUsers(ctx context.Context) ([]*User, error) {
+	query := `SELECT id, username, password, phone_number FROM users`
+
+	rows, err := s.db.Query(ctx, query)
+	if err != nil {
+		return nil, fmt.Errorf("querying all users: %w", err)
+	}
+	defer rows.Close()
+
+	var users []*User
+	for rows.Next() {
+		var user User
+		if err := rows.Scan(
+			&user.Id, &user.Username, &user.Password, &user.PhoneNumber,
+		); err != nil {
+			return nil, fmt.Errorf("scanning user row: %w", err)
+		}
+		users = append(users, &user)
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterating user rows: %w", err)
+	}
+
+	return users, nil
+}
+
+func (s *PGUserStore) UserExists(ctx context.Context, username string) (bool, error) {
+	query := `SELECT EXISTS(SELECT 1 FROM users WHERE username = $1)`
+
+	var exists bool
+	err := s.db.QueryRow(ctx, query, username).Scan(&exists)
+	if err != nil {
+		return false, fmt.Errorf("checking if user exists: %w", err)
+	}
+
+	return exists, nil
+}